Here is something you may find interesting. In various games there are special features that can make mapping very easy even in 3D games (if any 3D mappers are up to it). For example after playing and finishing the Playstation game "Medal of Honour" (The first one), I have found an unlockable special feature in the Secret Codes section called the "wireframe mode" which would be handy if you wanted to map that game. I'm not sure how many 3D games contain that feature but be sure to keep a sharp eye for any interesting content in the game besides gameplay.

It's one thing to be able to see the polygons and another to actually have the polygons. The wireframes are fun to look at, I imagine, but going in and trying to recreate it yourself in 3D by looking at lines on a screen would be so ridiculously time-consuming and difficult that it would make it practically impossible to do.

I've never heard of any other games that have a feature like that, but I would much rather have a way to rip model data from the game instead.

Odd that they would retitle something merely used for debugging as a "special feature" (suppose that since it was already in there anyway, they just left it as a freebie). Though, wireframe is far more useful for finding hidden sections on the map than actually constructing the map.

Model data is, of course, optimal, but so specific to each game. If I only knew more about the rendering hardware for anything N64 and later - maybe write to specific registers to set identity+translation and eliminate that irritating projection matrix...

Here is an interesting screenshot of a half-finished map from the Special Features Gallery in "Medal of Honor Underground". I begin to wonder of any fully finished maps in that format can be extracted from the game itself. It's not everyday you find something like this in a game.